import { beforeEach, describe, expect, it, jest } from "@jest/globals";
import { NotificationService } from "../../src/services/NotificationService";
import { UnoptimizedInMemoryRepository } from "../../src/repositories/UnoptimizedInMemoryRepository";
import fs from "fs";
import http2 from "http2";
import { IEta, IShuttle, IStop } from "../../src/entities/entities";
import { addMockShuttleToRepository, addMockStopToRepository } from "../testHelpers/repositorySetupHelpers";
import EventEmitter = require("node:events");

jest.mock("fs");
jest.mock("http2");

const sampleKey = `-----BEGIN PRIVATE KEY-----
MIGTAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBHkwdwIBAQQgsrmSAZIagOfCP8sB
Wi2CBXG1Oo7v1bispIZCwIr4RDegCgYIKoZIzj0DAQehRANCAATZHxV2wQJLMBq+
ya+yfGi3g2ZUv6hrfe+j08ytekPHjXS0qzJoVELzKHa6EL9YAoZDXBtB6h+fGhXe
SOcONbaf
-----END PRIVATE KEY-----`

/**
 * Wait for a condition to become true until the timeout
 * is hit.
 * @param condition
 * @param timeoutMilliseconds
 * @param intervalMilliseconds
 */
async function waitForCondition(condition: () => boolean, timeoutMilliseconds = 5000, intervalMilliseconds = 500) {
  const startTime = Date.now();
  while (!condition()) {
    if (Date.now() - startTime > timeoutMilliseconds) {
      throw new Error("Timeout waiting for condition");
    }
    await new Promise((resolve) => setTimeout(resolve, intervalMilliseconds));
  }
}

/**
 * Wait for a specified number of milliseconds.
 * @param ms
 */
async function waitForMilliseconds(ms: number): Promise<void> {
  await new Promise((resolve) => setTimeout(resolve, ms));
}

function mockHttp2Connect(status: number) {
  class MockClient extends EventEmitter {
    request = jest.fn((headers: any) => {
      const mockRequest: any = new EventEmitter();
      mockRequest.setEncoding = jest.fn();
      mockRequest.write = jest.fn();
      mockRequest.end = jest.fn(() => {
        setTimeout(() => {
          mockRequest.emit('response', { ':status': status });
        }, 10);
      });
      return mockRequest;
    });

    close() {};
  }

  (http2.connect as jest.Mock) = jest.fn(() => new MockClient());
}

describe("NotificationService", () => {
  let repository: UnoptimizedInMemoryRepository
  let notificationService: NotificationService;

  beforeEach(() => {
    repository = new UnoptimizedInMemoryRepository();
    notificationService = new NotificationService(repository);

    // Ensure that tests don't hit the server
    process.env = {
      ...process.env,
      APNS_KEY_ID: "1",
      APNS_TEAM_ID: "1",
      APNS_KEY_PATH: "./dummy-path.p8",
      APNS_BUNDLE_ID: "dev.bchen.ProjectInter"
    };

    (fs.readFileSync as jest.Mock).mockReturnValue(sampleKey);
  });

  beforeEach(() => {
    mockHttp2Connect(200);
  });

  describe("reloadAPNsTokenIfTimePassed", () => {
    it("reloads the token if token hasn't been generated yet", async () => {
      notificationService.reloadAPNsTokenIfTimePassed();
      expect(notificationService.lastRefreshedTimeMs).toBeDefined();
    });

    it("doesn't reload the token if last refreshed time is recent", async () => {
      notificationService.reloadAPNsTokenIfTimePassed();
      const lastRefreshedTimeMs = notificationService.lastRefreshedTimeMs;

      notificationService.reloadAPNsTokenIfTimePassed();
      // Expect no change to have occurred
      expect(lastRefreshedTimeMs).toEqual(notificationService.lastRefreshedTimeMs);
    });
  })

  function generateNotificationDataAndEta(shuttle: IShuttle, stop: IStop) {
    const eta: IEta = {
      shuttleId: shuttle.id,
      stopId: stop.id,
      secondsRemaining: 120,
    };

    const notificationData1 = {
      deviceId: "1",
      shuttleId: eta.shuttleId,
      stopId: eta.stopId,
    }
    const notificationData2 = {
      ...notificationData1,
      deviceId: "2",
    }
    return { eta, notificationData1, notificationData2 };
  }

  describe("scheduleNotification", () => {
    it("schedules the notification", async () => {
      // arrange
      const notificationData = {
        deviceId: "1",
        shuttleId: "1",
        stopId: "1"
      };

      await notificationService.scheduleNotification(notificationData);

      const isNotificationScheduled = notificationService.isNotificationScheduled(notificationData);
      expect(isNotificationScheduled).toEqual(true);
    });

    it("sends and clears correct notification after ETA changed", async () => {
      // Arrange
      const shuttle = await addMockShuttleToRepository(repository, "1");
      const stop = await addMockStopToRepository(repository, "1");

      const { eta, notificationData1, notificationData2 } = generateNotificationDataAndEta(shuttle, stop);

      // Act
      await notificationService.scheduleNotification(notificationData1);
      await notificationService.scheduleNotification(notificationData2);
      await repository.addOrUpdateEta(eta);

      // Assert
      // Because repository publisher calls subscriber without await
      // wait for the change to occur first
      await waitForCondition(() => !notificationService.isNotificationScheduled(notificationData1));

      const isFirstNotificationScheduled = notificationService.isNotificationScheduled(notificationData1);
      const isSecondNotificationScheduled = notificationService.isNotificationScheduled(notificationData2);
      // No longer scheduled after being sent
      expect(isFirstNotificationScheduled).toBe(false);
      expect(isSecondNotificationScheduled).toBe(false);
    });

    it("doesn't send notification if seconds threshold not exceeded", async () => {
      // Arrange
      const shuttle = await addMockShuttleToRepository(repository, "1");
      const stop = await addMockStopToRepository(repository, "1");
      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop);
      eta.secondsRemaining = notificationService.secondsThresholdForNotificationToFire + 100;

      // Act
      await notificationService.scheduleNotification(notificationData1);
      await repository.addOrUpdateEta(eta);

      // Assert
      await waitForMilliseconds(500);
      const isNotificationScheduled = notificationService.isNotificationScheduled(notificationData1);
      expect(isNotificationScheduled).toBe(true);
    });

    it("leaves notification in array if delivery unsuccessful", async () => {
      // Arrange
      const shuttle = await addMockShuttleToRepository(repository, "1");
      const stop = await addMockStopToRepository(repository, "1");
      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop)
      mockHttp2Connect(403);

      // Act
      await notificationService.scheduleNotification(notificationData1);
      await repository.addOrUpdateEta(eta);

      // Assert
      // The notification should stay scheduled to be retried once
      // the ETA updates again
      await waitForMilliseconds(500);
      const isNotificationScheduled = notificationService.isNotificationScheduled(notificationData1);
      expect(isNotificationScheduled).toBe(true);
    });
  });

  describe('getAPNsFullUrlToUse', () => {
    it('should return the production URL when NODE_ENV is set to "production"', () => {
      process.env.NODE_ENV = 'production';
      const deviceId = 'testDeviceId';
      const result = NotificationService.getAPNsFullUrlToUse(deviceId);

      const { fullUrl, host, path } = result;
      expect(fullUrl).toBe(`https://api.push.apple.com/3/device/${deviceId}`);
      expect(host).toBe("https://api.push.apple.com");
      expect(path).toBe(`/3/device/${deviceId}`);
    });

    it('should return the sandbox URL when NODE_ENV is not set to "production"', () => {
      process.env.NODE_ENV = 'development';
      const deviceId = 'testDeviceId';
      const result = NotificationService.getAPNsFullUrlToUse(deviceId);

      const { fullUrl, host, path } = result;
      expect(fullUrl).toBe(`https://api.development.push.apple.com/3/device/${deviceId}`);
      expect(host).toBe("https://api.development.push.apple.com");
      expect(path).toBe(`/3/device/${deviceId}`);
    });
  });

  describe("cancelNotification", () => {
    it("stops notification from sending to given shuttle/stop ID", async () => {
      // Arrange
      const shuttle = await addMockShuttleToRepository(repository, "1");
      const stop = await addMockStopToRepository(repository, "1");
      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop);

      await notificationService.scheduleNotification(notificationData1);

      // Act
      await notificationService.cancelNotificationIfExists(notificationData1);
      await repository.addOrUpdateEta(eta);

      // Assert
      await waitForMilliseconds(500);
      expect(http2.connect as jest.Mock).toHaveBeenCalledTimes(0);
    });
  });
});